1. Field of the Invention
The present invention relates to a photosensitive conductor paste that can form electrode patterns with high accuracy.
2. Background Art
In recent years, formation of fine patterns with higher accuracy at lower production cost has become required of the production of electrodes and the like in plasma display panels (PDP).
Electrode patterns in PDP have hitherto been formed, for example, by a printing method wherein a paste containing a conductive powder for patterns is printed by screen printing, offset printing or the like to form a predetermined pattern which is then dried and fired to form an electrode pattern.
The printing method is simple and can be expected to reduce the production cost. The printing method, however, suffers from the following drawbacks. Specifically, screen printing is disadvantageous in that there is a limitation in the accuracy of printing due to elongation of a mesh material constituting a screen printing plate. In addition, traces of the mesh are created in the pattern, or blurring of the pattern is created. This poses a problem of the accuracy in the edge shape of the electrode pattern. On the other hand, for the offset printing, with increasing the number of times of printing, the paste for the pattern is left on a blanket without being fully transferred onto a substrate. This lowers the accuracy of the pattern. For this reason, in order to maintain the accuracy of the pattern, the blanket should be replaced as the occasion demands to prevent leaving of the paste on the blanket. This procedure is very troublesome.
For the solution to the above problems, a method is considered effective which comprises the steps of: providing a photosensitive paste containing a conductive powder; forming a photosensitive conductor layer on a substrate by coating or transfer; subjecting the photosensitive conductor layer to exposure and development through a predetermined photomask; and firing the developed conductor layer to remove organic components, thereby forming an electrode pattern.
The conventional photosensitive conductor paste suffers from poor dispersibility of solid matter such as a conductive powder, poor developability, unsatisfactory photosensitivity, and poor edge shape of the electrode pattern. Therefore, it is difficult to form electrode patterns with high accuracy from the conventional photosensitive conductor paste.
The present invention has been made under the above circumstances, and it is an object of the present invention to provide a photosensitive conductor paste that can form high-definition electrode patterns.